Fact: i do own a gun.
Why: i don't need a reason why. I am legally entitled to do so, so giving reasons isn't necessary, any more than i need to give my reasons for choosing a silver Saturn sedan, rather than a blue Chrysler convertible.
If you were truly interested in my reasons for owning a gun, i rather enjoy shooting my Sig Sauer as a hobby, and measure of skill - in short, a recreational pursuit. The fact that it could be used as a self-defense tool is a secondary, but real, consideration. Self-defense was not my primary consideration, any more than it was in the selection of my kitchen knives, which i could also use for self-defense if it came right down to it.
Whether or not you like the idea of citizens' rights to own weapons, it IS a Constitutionally guaranteed right in America.